Two major problems in schema integration are to identify correspondences between different conceptual schemas and to verify that the proposed correspondences are consistent with the semantics of the schemas. This problem can only be effectively addressed if the conceptual schema is expressed in a semantically rich modelling formalism. We introduce such a modelling formalism, the distinguishing ...

Two major problems in constructing data federations (for example, data warehouses and database federations) concern achieving and maintaining consistency and a uniform representation of the data on the global level of the federation. The first step in creating uniform representations of data is known as data extraction, whereas data reconciliation is concerned with resolving data inconsistencie...

this paper describes a simple, physically-based conceptual model utilizing watershed drainage characteristics for rainfall-runoff simulation. this conceptual physiographic model is essentially based on the work of najafi (2003), which has led to a model compris-ing the main tributary subwatersheds and a single main channel subwatershed. the ki-nematic wave (kw) theory is used to describe flow o...

Object-Role Modeling (ORM) is a framework for modeling and querying information at the conceptual level. It comes to support the design of large-scale industrial applications allowing the users to model easily the domain. The reasoning on a conceptual schema enables to automatically detect relevant formal properties, such as inconsistencies or redundancies that cause a degradation of the qualit...

The UML is a non-temporal conceptual modeling language. Conceptual schemas in the UML assume that the information base contains the current instances of entity and relationship types. For many information systems, the above assumption is acceptable. However, there are some information systems for which that assumption is a severe limitation. This happens when the functions of the information sy...

The next generation of task support systems aims at providing the relevant knowledge to knowledge-dependent activities, reducing the effort required to find or infer this knowledge from the data. In order to exploit knowledge associated with (or embedded in) databases and to migrate from data to knowledge management environments, conceptual modeling languages must offer more expressiveness than...

In the traditional systems modeling approach, the modeler is required to capture a user’s view of some domain in a formal conceptual schema. The designer’s conceptualization may or may not match with the user’s conceptualization. One of the reasons for these conflicts is the lack of an initial agreement among users and modelers concerning the concepts belonging to the domain. Such an agreement ...